Portable kiln



May 23, c 5 BANG PORTABLE KILN Filed April 19, 1937 Patented May 23,1939 UNITED STATES PATENT OFFICE Application. April 19, In Canada 6laims.

This invention relates to kilns and more particularly for those employedin the carbonization of wood and the production of charcoal.

The object of my invention is to provide a kiln in which the escapingheated gases pass through the hollow walls and form an insulating jacketto the chamber in which the treatment is being carried on.

A further object is to provide a kiln of a portable weight mounted ontrunnions on a stand whereby it can be readily tilted to a horizontalposition to facilitate the filling and emptying operations.

A further object is to provide a means to charge the kiln with wood inan improved manner whereby a higher grade of charcoal is produced.

Other objects will be set forth hereafter.

Reference is made to the accompanying drawing in which:

Figure 1 is a side view of the kiln partly in section.

Figure 2 shows the kiln mounted on its stand and the means of tiltingit.

Figure 3 is a cross section of Figure 1 on the line 33 lookingdownwards.

Figure 4 is a plan view.

As shown in Figure 1 the kiln is in the form of a cylinder I, havingslightly conical top l9 and bottom H. An inner wall I2, and lower top !3provide a connected passage to a central outlet I l. The top l3 has alsoa central opening l5.

Towards the lower part of the wall I a plate 16 cuts the passage betweenthe walls l and I2 into an upper passage l1 and a lower passage l8. Acontinuous opening l9 above the plate It provides' an entrance from theinterior of the kiln 2 to the passage H. An opening 2! at the bottom ofthe inner wall [2 provides an inlet from the passage [8 into theinterior 2. A series of valved inlets 22 to the passage l8 provide thecontrol of the air supply to the kiln. The bottom H is provided with twoor more manholes 23 with covers 24. In the center of the bottom ll,there is an outlet 25 into a pipe 26 to provide for the removal of thefluid products of the treatment. Half way up the inner wall i2 isa ringor plate 21 secured by vertical supports to that wall to permit the freeflow of gas down the wall to the outlet I9. The outlet 25 has a cover orgrating 28 with open sides 29 to protect it from being blocked by solidmatter from above.

The cylinder I is provided with a pair of trunnions 3 firmly secured tothe outer and inner walls. 0n the outer edge of the top H] at points1937, Serial No. 137,789 April 25, 1936 at right angles to the trunnions3 are secured rings 30 to connect with the tilting apparatus.

The outlet 14 has an adjustable cover 3| to control the escaping gasesand smoke. The outlet 15 has a cover 32 adapted to a sand seal.

The stand 4 has suitable bearings for the trunnions 3 at a heightsufiicient to permit the kiln to rotate freely. The side members M ofthe stand 4 are connected at one end of their bases by a bar 42 on whichare mounted, at the middle a block 43 and at one end a block 44. Theside member 4| extends upwards a distance above the top of the kiln whenmounted on its trunnions 3 and at its upper end has a bracket to which ablock 46 is hooked. A rope 5 with a hook 5G is attached to the ring 30and passes through the blocks 43, 44 and 46 and is connected to aperforation at the lower end of the side member 4| by a block and tackle47 or similar mechanism.

Beneath the outlet pipe 26 is placed a deep pan 6 to receive the liquidoutflow from the kiln and to provide a water seal to the pipe 2'6.

With a construction similar to that above described, the operation ofthe device is as follows:

In order to charge the kiln with the logs of wood to be treated, bymeans of the block and tackle the kiln is rotated into a horizontalposition and the manhole covers are removed. The wood in logs about halfthe length of the kiln, are then placed in the interior in the positionas shown in Figure 1. Owing to the ring or plate 21 the upper tier ofthe logs will incline outwardly, while the lower tier will inclineinwardly. This arrangement provides an unobstructed passage for thesmoke and gases down the inner wall l2 to the opening IE to the wallpassages I! and thence to the outlet M.

When the kiln has been fully charged with logs, the covers over themanholes are replaced and secured, and the kiln is tilted back to avertical position.

The charge of wood is then ignited through the top openings. The lowertop opening has its cover adjusted and is preferably sealed by a sandseal. This sand seal acts as a safety valve to the interior of the kiln,should the pressure of the gases become too high.

The air inlets are then adjusted to supply the required amount of air.The top cover is then adjusted to provide a suificient draught throughthe kiln. Readjustment of the air valves and the top cover will be madeduring the operation of the treatment.

The pan is placed under the bottom outlet pipe, and filled withsufficient water to provide a water seal to the pipe.

Owing to the interior of the kiln being surrounded by a heated area, thewalls are prevented from cooling, however low the external temperaturemay be. The efiect of this protection is that the process ofcarbonization of the charge of Wood takes place more uniformly than hashitherto been possible.

Furthermore, by arrangingthe charge oflogs in the kiln in the mannershown in Figure 1, the circulation and removal of the gases ismaintained throughout the operation and a uniform treatment is obtained.As both tiers of the charge will descend toward the center of the kilnas shrinkage takes place, there is less liability of the product beingbroken up.

By these means, a higher quality of charcoal is produced and also ahigher percentage of the charge is converted intocharcoal and is notconsumed in the process.

The outlet pipe at the bottom of the kiln provides for the rapid removalof the liquid prodnets of the treatment. The cover or grating pree ventsthe solid charge from blockingthis outlet, while the water seal preventsthe escape of gas through the outlet pipe.

.When the process of carbonization has been completed, the air inletsare closed, and the cover of the gas outlet is secured in a closedposition. The kiln is then allowed to cool off before the removal of thecharcoal.

After cooling the kiln is again tilted to a horizontal position, themanhole covers removed and the product of the treatment is withdrawn. Itis obvious that the shape of the kiln is not limited to a cylindricalform, but may be rnade inv other'suitable forms with similar functions.

What I claim is:

1. In a portable kiln, a shell supported by trunnions ona stand, havingdouble Walls, forming an annular vertical flue, end platesto the wallsproviding a passage from the top of the flue-to a central outlet, ahorizontal dividing plate betweenthe walls below an opening from the interiorof the kiln in its lower portion, air inlets to the flue below theplate, with an outlet from this-portion of the flue to the interior ofthe kiln at its bottom, openings in the bottom of the kiln for insertingthe charge, and a central outlet in the bottom and means to tilt thekiln to a horizontal position.

2. In a portable kiln, a shell supported by trunnions on a stand, havingdouble walls forming an annular vertical flue, end plates to each wallforming a passage from the top ofthe flue to a central controlled outletin the upper end plate, a horizontal dividing plate at the lowerportionof the-walls forming upper and'lower flues, an outlet from theinterior of the kiln to the upper flue above the plate, air inlets tothe flue below the plate and outlets from this portion of the flue tothe bottom space of the kiln, man holes in the bottom of the kiln forcharging and emptying the kiln, a central outlet in-the bottom having awater seal and a central outlet in the top of the kiln having a coverthereto and means to tilt the shell to a horizontal position.

3. In a portable kiln, a shell supported by trunnions on a stand, havingdouble walls forming an annular vertical flue, end plates to each wallforming a passage from the top of the flue to a central controlledoutlet in the upper end plate, a horizontal dividing plate at the lowerportion of the walls forming upper and lower flues, an outlet from theinterior of the kiln to the upper flue above the plate, air inlets tothe flue below the plate and outlets from this portion of the flue tothe bottom space of the kiln, man holes in the bottom of the kiln forcharging and emptying the kiln, a central outlet in the bottom having awater. seal and a central outlet in the top of the kiln having a coverthereto, a narrow plate with vertical supports a short distance withinthe middle of the inner wall, and means to tilt the shell to ahorizontal position.

4. In a portable kiln, a shell supported by trunnions on a stand havingdouble walls formingan annular vertical flue, end plates to the outerwalls forming top and bottom to the kiln, an upper. end.

plate to the inner wall, central outlets to the top end plates the lowerportion of the flue being cut off by a horizontal plate below an openingin the inner wall to the interior of the kiln, a series of controlledair inlets in the outer wall to the flue below the horizontal plate,which flue opens to the interior of the kiln at its bottom, openings inthe bottom of the kiln and means to tilt the kiln to a horizontalposition. a K

5. Ina portable kiln, an outer shell supported by trunnions on a standhaving slightly conical top and bottom, a central outlet to the top,openings in the bottom to insert the charge, an inner shell having a topforming an annular flue lead: ing to the central outlet, an opening inthe inner shell in its lower portion a horizontal plateinthe flue belowthe opening cutting off the section below the plate, which section'opensat its bottom to the interior of'the kiln, a series of controlled airinlets to thissectionof the flue and top and bottom, a central outlet tothe top, openings in the bottom to insert the charge, an inner shellhaving a top forming an annular flue leading to the central outlet, an.opening in the innershell in its lower portion, a horizontal plate inthe flue below the op ning cutting off the section below the plate,which section opens at its bottom to the interior of the kiln, a seriesof controlled air inlets to this section of the flue, an outlet in thetop of the inner shell below the central outlet and an outlet in thecenter of the bottom of the kiln, and means to tilt the kiln to ahorizontal position for filling and emptying the charge.

